Svelter libart-compiler

Added new environment variable ART_{TARGET,HOST}_CODEGEN_ARCHS which
may be set to 'all', 'svelte' or a space separated list of architectures.

When compiled with ART_{TARGET,HOST}_CODEGEN_ARCHS='all' (the default
value) dex2oat will be able to generate output for all supported
architectures.

When compiled with ART_TARGET_CODEGEN_ARCHS='svelte'
only the architectures of the TARGET will be included. When
ART_HOST_CODEGEN_ARCHS='svelte' all architectures the target includes
and the host architectures will be included on the host dex2oat.

If a list of architectures is given only those will be included.

Change-Id: I87f4ad0131ab1b37544d8799e947ce4733b6daec
diff --git a/compiler/utils/assembler.cc b/compiler/utils/assembler.cc
index 6d8a989..496ca95 100644
--- a/compiler/utils/assembler.cc
+++ b/compiler/utils/assembler.cc
@@ -19,13 +19,25 @@
 #include <algorithm>
 #include <vector>
 
+#ifdef ART_ENABLE_CODEGEN_arm
 #include "arm/assembler_arm32.h"
 #include "arm/assembler_thumb2.h"
+#endif
+#ifdef ART_ENABLE_CODEGEN_arm64
 #include "arm64/assembler_arm64.h"
+#endif
+#ifdef ART_ENABLE_CODEGEN_mips
 #include "mips/assembler_mips.h"
+#endif
+#ifdef ART_ENABLE_CODEGEN_mips64
 #include "mips64/assembler_mips64.h"
+#endif
+#ifdef ART_ENABLE_CODEGEN_x86
 #include "x86/assembler_x86.h"
+#endif
+#ifdef ART_ENABLE_CODEGEN_x86_64
 #include "x86_64/assembler_x86_64.h"
+#endif
 #include "globals.h"
 #include "memory_region.h"
 
@@ -112,20 +124,32 @@
 
 Assembler* Assembler::Create(InstructionSet instruction_set) {
   switch (instruction_set) {
+#ifdef ART_ENABLE_CODEGEN_arm
     case kArm:
       return new arm::Arm32Assembler();
     case kThumb2:
       return new arm::Thumb2Assembler();
+#endif
+#ifdef ART_ENABLE_CODEGEN_arm64
     case kArm64:
       return new arm64::Arm64Assembler();
+#endif
+#ifdef ART_ENABLE_CODEGEN_mips
     case kMips:
       return new mips::MipsAssembler();
+#endif
+#ifdef ART_ENABLE_CODEGEN_mips64
     case kMips64:
       return new mips64::Mips64Assembler();
+#endif
+#ifdef ART_ENABLE_CODEGEN_x86
     case kX86:
       return new x86::X86Assembler();
+#endif
+#ifdef ART_ENABLE_CODEGEN_x86_64
     case kX86_64:
       return new x86_64::X86_64Assembler();
+#endif
     default:
       LOG(FATAL) << "Unknown InstructionSet: " << instruction_set;
       return nullptr;